Crank/flywheel seal - whats best?

[SorenDK]

hi everybody - this has probably been discussed before but I cannot find the post: what is the seal to use at the crank/flywheel? I have heard about orange, black and two-tone seals?
My car is a 1977 2,7 liter - its newly rebuild and unfortunately leaking so have examine and change seal.

Thanks from Søren

[rsscotty]

We have had nothing but leak problems with Elring (dark red) & KACO (white) flywheel seals.
Started using Victor Reinz and all leaks went away.

[franklinstower]

We have had nothing but leak problems with Elring (dark red) & KACO (white) flywheel seals.
Started using Victor Reinz and all leaks went away.

interesting,
I just put in the Elring seal based on other posts I read that said the other (kaco and Reinz) were prone to leak....

The Kaco I pulled out was trashed, but was probably in there since the early 90's.

Is your experience that the Kaco and Elring are leaking at the case or the crankshaft?

[gomezoneill]

One of the most important things is to install the seal with the correct tool no matter the manufacturer (of the seal). I see guy's using pipes and PVC to install the seals. Not the right way to do things. The right tool for the job especially with these cars.

[85eurocarrera]

Order at least two of them. Mess one up, you have another ready to go.

[manbridge 74]

Seals get old on the shelf. When you buy from Porsche they come sealed in a bag with a date on it. Usually within the last six months.

[tobluforu]

Originally Posted by 85eurocarrera

Order at least two of them. Mess one up, you have another ready to go.

This^^^. Few things to add, prep is key. Make sure you de-burr the cavity; make sure that when you press it in that it isn't in the same place as the old, and if done right you don't even need a tool. A little curil-t, freeze it and it will slide right in.

[SorenDK]

I have heard about the freeze-trick before - it makes them shrink i assume. Some also suggest soaking them in oil overnight. What about the bi-colored... usable?

I have read about a guy who shortened the spring in the seal with a couple of mm's ... any thoughts on this?

Søren

[chris_seven]

We had some issues recently and had a PTFE seal made which worked well but I prefer the idea of shortening the spring as recommended by Henry Schmidt.

Any R21 or R23 seal made of Viton should be OK and the idea of soaking them in oil doesn't make sense.

NBR Seals just won't cope with the speed and will wear rapidly.

I think this was a trick for the really old 'Rope' seals used in the Fifties.

[KTL]

As Chris alluded to, the only reason to shorten the garter spring within the seal is to make it seal tighter. The reason that is typically done is when the crankshaft flange is machined smaller to resurface the sealing area, usually on account of the seal wearing a groove into the surface.

The seal kits that are said to be the best are made by Wrightwood Racing and they apparently hand select the various seals and gaskets and crush washers from various suppliers to make their complete kits. The crank seals that Wrightwood uses are the bi-colored seals. Ironically, with respect to the comments in this discussion, they are made by Elring-Klinger last I saw.

Interesting that the seals would get old on the shelf. How is that different or worse than a seal getting old sitting in an engine? I think the seal on the shelf would age better? Not trying to be a jerk. Trying to understand what makes a seal go bad sitting in storage because I have a bunch of them in a cardboard box. Everybody local to me seems to make me their Porsche parts charity after they sell their cars. So i have a ridiculous number of radial seals like these for Porsche crankshafts and transmissions

These seals should be installed "dry" in that you only wet them to get them in place and that wetness should eventually dry up. So wipe some water or spit on the seal outside diameter and inside the engine case bore. Lubing them with oil or that green Curil T sticky goop is bad practice and you're inviting the seal to leak or walk its way out of the bore. Seen it happen many many times on this forum. The only thing that should be lubed is the inside diameter to allow the seal lip to ride lubricated on the crankshaft until the engine builds oil pressure and lubes the lip from the inside.

If one is driving the seal into the bore with a hammering method, it's a good idea to put some grease on the garter spring in a few locations to keep it from popping off the seal while it's taking the pounding of your installation.

[chris_seven]

Viton Seals should, according to DOW Chemicals, have an unlimited shelf life so age shouldn't be much of an issue.



We have been using Viton R23 double lip seals manufactured by Fairway Seals in the UK and are local to our shop.

Oil Seal Rotary Shaft Seal R23 - Fairway Seals

I have been trying to have been trying to have some R22 profile seals made but no-one seems able to make this style in Viton and NBR just doesn't deal with the speed.

[SorenDK]

These are great points to consider. I agree that Viton would be the best material to use. Chris - The R23 double lip seal by Fairway. Where can I obtain these?

[manbridge 74]

Well nothing stays ductile forever otherwise seals would never get hard and leak. But perhaps I just prefer seals that aren't exposed to all the typical contaminants found in a shop environment or just from being mishandled over the years. I have seen rust on garter springs before.

[chris_seven]

Originally Posted by SorenDK

These are great points to consider. I agree that Viton would be the best material to use. Chris - The R23 double lip seal by Fairway. Where can I obtain these?

PM your address and I will post you one.

Exceptions are the metal-cased HDS seals and the rubber cased HS seals that are designed with stainless steel garter springs

[Uwon]

Subscribed.
Johan

[SorenDK]

Chris_seven - are you out there? Have PM but heard nothing.?? In case Chris is out does anyone else know about the double lip seals mentioned here? I think it sounds to be a good solution. I have contacted the factory by the way.
Cheers from Søren

[tyro]

Same deal as the 944 2.5l, I had the best luck with Elring seal, seems it was not the same color throughout.

A little Curil T on the outside and sir tools seal arbor (P234) made it a good seal.

I guess I wrote something on rennlist in 2007 about it: Rear Main Seal Install Depth - Page 2 - Rennlist Discussion Forums